Tires are commonly manufactured using of one or more building drums upon which the tire is constructed from multiple layers and components that are placed sequentially onto the drum. For example, in one technique, a layer of air impermeable rubber is laid onto the forming surface of a cylindrical drum. One or more carcass plies are placed onto the drum. A pair of circular beads are placed on opposing sides and may include bead wires and bead fillers. The plies are turned up and the beads are moved towards each other to create a toroidal shape. A sidewall protective rubber and a tread portion are added.
The addition of rubber elements into the sidewalls of the tire can be desirable for certain tire applications. For example, the addition of rubber reinforcements into the sidewalls can be used along with other features to provide a tire that is capable of operating for a limited distance after losing inflation pressure. Such may allow the driver to reach a service center or other location more suitable than where the pressure loss occurred.
Certain challenges, however, are presented in the manufacture of tires having e.g., reinforcement in the sidewalls. The forming drum is typically a cylindrical shape having a flat profile along the axial direction but may have recesses for accepting features such as circular beads. For designs where these reinforcements are presented onto the forming drum before a carcass ply or reinforcing ply is laid onto the forming drum, the reinforcements create a profile that is no longer flat along the axial direction of the drum. Presentation of a carcass ply onto this uneven profile can result in undesirable creases or wrinkles—particularly when attempting to press the carcass ply towards the forming drum to make contact with e.g., an air impermeable layer on the forming drum. In turn, these creases can lead to an undesirable orientation and positioning of cords and/or other reinforcing elements present in the reinforcing ply—referred to herein as deradialization. Also, the joining of the ends of the ply may no longer be uniform as the amount of overlap may be quite variable.
Accordingly, a method for assembling a tire having one or more reinforcements or supports in the sidewalls would be useful. More particularly, such a method that can be used to reduce or avoid creases or wrinkles that can lead to deradialization and/or non-uniformities in the joining of the ends of the plies would be beneficial.